1. Field of the Invention
The invention relates to potential detection on a high-voltage line, and particularly to a detection device including a potential-detection plate mounted on a standard suspension insulator.
2. Description of the Prior Art
Computerized supervisory control systems are being installed for use in existing electric power systems everywhere. The most useful supervisory control systems are those designed to indicate the status of the entire power system. Such remote control systems therefore will indicate energized-deenergized status of many substation bus and transmission line sections which presently have no devices to provide this monitoring.
The present method of determining the energized or deenergized condition of the high-voltage power lines using the capacitive voltage divider method is with high-voltage coupling capacitors or capacitive voltage taps in high-voltage bushings of transformers, circuit breakers or other similar pieces of equipment. The present method is somewhat expensive and, therefore, limits the number of coupling capacitors or bushing potential devices to be used on a particular system. Potential transformers and resistance type potential devices are also available, but the costs are still high and permanent additional space and mountings are needed for each device. The coupling capacitor, potential transformer, resistance type potential device, and voltage tap of a high-voltage apparatus bushing all give indication of an energized condition but also are designed to accurately indicate the voltage level of the power line they are attached to, making these devices more expensive than is necessary for a simple potential detector. But simple potential detection is all that is needed to determine if a section of transmission line is operative.
In higher voltage electrical transmission systems, systems such as are described in U.S. Pat. Nos. 3,343,153, 3,390,331, 3,425,049, 3,513,394, 3,656,057 and 3,736,505 are of limited usefulness.
For voltages such as 230-kV, 345-kV, 500-kV, or 750-kV, the use of insulated cable systems is very limited due to adverse inherent electrical characteristics of electrical insulations developed to date. Therefore, capacitive voltage detectors for indication of energized cable as described in these patents would have no application for these higher voltage systems. Also, separation would be accomplished by means of special switches rather than cable-to-transformer connectors as described.